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Abstract: Novel glycerol crosslinked poly(methyl methacrylate)(PMMA) was synthesized in one step in the presence of cocktail of chemical initiator and the biocatalyst Novozym 435 under mild reaction conditions. The objective of the study was to investigate the feasibility of glycerol to crosslink PMMA by biocatalytic route and to explore glycerol crosslinked PMMA as controlled release vehicle Effect of reaction time, temperature, glycerol to methylmethacrylate ratio, and methacrylate to toluene ratio was studied. Glycerol crosslinked PMMA swelled 289(±9)% in acetone and collapsed when immersed in water and in hexane. Swelling and shrinking of glycerol crosslinked PMMA was reversible in nature. Nanoparticles of glycerol crosslinked poly(methyl methacrylate) were synthesized by nanoprecipitation technique. The particles were spherical and of nanosize. The nanoparticles were used for the encapsulation and release of mosquito repellent N,N-diethyl-m-toluamide. Nanoparticles could encapsulate 8.5mg of repellant in 4h. The repellant got released from the nanoparticles at a controlled rate for a prolonged time interval. Release was more pronounced in deionized water and pH 7 buffer than in acetone. Addition of 1% NaCl further improved the release profile. 80% of encapsulated repellant was released from the nanoparticles in pH 7 buffer with 1% NaCl. [Copyright &y& Elsevier]

This roadmap reviews the new, highly interdisciplinary research field studying the behavior of condensed matter systems exposed to radiation. The Review highlights several recent advances in the field and provides a roadmap for the development of the field over the next decade. Condensed matter systems exposed to radiation can be inorganic, organic, or biological, finite or infinite, composed of different molecular species or materials, exist in different phases, and operate under different thermodynamic conditions. Many of the key phenomena related to the behavior of irradiated systems are very similar and can be understood based on the same fundamental theoretical principles and computational approaches. The multiscale nature of such phenomena requires the quantitative description of the radiation-induced effects occurring at different spatial and temporal scales, ranging from the atomic to the macroscopic, and the interlinks between such descriptions. The multiscale nature of the effects and the similarity of their manifestation in systems of different origins necessarily bring together different disciplines, such as physics, chemistry, biology, materials science, nanoscience, and biomedical research, demonstrating the numerous interlinks and commonalities between them. This research field is highly relevant to many novel and emerging technologies and medical applications. [ABSTRACT FROM AUTHOR]

Aromatic self-assembled monolayers (SAMs) can serve as platforms for development of supramolecular assemblies driven by surface templates. For many applications, electron processing is used to locally reinforce the layer. To achieve better control of the irradiation step, chemical transformations induced by electron impact at 50 eV of terphenylthiol SAMs are studied, with these SAMs serving as model aromatic SAMs. High-resolution electron energy loss spectroscopy (HREELS) and electron-stimulated desorption (ESD) of neutral fragment measurements are combined to investigate electron-induced chemical transformation of the layer. The decrease of the CH stretching HREELS signature is mainly attributed to dehydrogenation, without a noticeable hybridization change of the hydrogenated carbon centers. Its evolution as a function of the irradiation dose gives an estimate of the effective hydrogen content loss cross-section, σ = 2.7-4.7 × 10-17 cm². Electron impact ionization is the major primary mechanism involved, with the impact electronic excitation contributing only marginally. Therefore, special attention is given to the contribution of the low-energy secondary electrons to the induced chemistry. The effective cross-section related to dissociative secondary electron attachment at 6 eV is estimated to be 1 order of magnitude smaller. The 1 eV electrons do not induce significant chemical modification for a 2.5 mC cm-2 dose, excluding their contribution. [ABSTRACT FROM AUTHOR]